This invention relates generally to assembling concrete form panels for use in casting concrete wall structures. More particularly it relates to improvements in apparatus provided to form the corners of a concrete cast wall structure and especially inside corners.
In the prior art, many different proposals have been offered with respect to form work and assembling such form work into functional units for concrete construction. Accordingly various structures have been suggested for use in positioning concrete form panels as required in casting the inside corner of a concrete wall structure. Forming such inside corners is necessary in providing concrete shafts, such as elevator shafts, and stairwells in building construction.
Ideally the finished inside corner is to be smooth and free from joint lines as might be created by the surface character of the form panel or other elements against which the concrete is cast. Importantly, the structure or apparatus utilized to cast the concrete inside corner thereagainst should be simple and involve a minimum number of structural elements. Certainly it is a disadvantage for the form panel support structure to involve use of a variety of separate detached or detachable elements which would be subject to being separated or lost to prevent reuse of the structure at different site locations.
The prior art structures have generally failed to permit obtaining all of the above mentioned advantages and to avoid the disadvantages outlined.
Accordingly one of the essential objects of this invention is to provide form panel apparatus for casting an inside corner structure which will render it possible to form the concrete wall structure with a smooth inner surface at and adjacent the corner with the apparatus being composed of a relatively few simple parts which are capable of being readily assembled and disassembled.
A principal object of the invention is the provision of an inside corner concrete form panel support structure with a minimum of individual parts such that there is less likelihood of any of the parts being lost or separated for the installation at which they are needed.
Another object of the invention is to provide a corner form panel structure which is adapted to extend across the space between the adjacent edges of wall forming panel sections at the corner of a shaft or other inside corner wall structure, in which a corner forming member has angularly related outer edges respectively overlapping and interengaging with the inner wall forming surfaces of the panel sections with a control unit operable to clamp the overlapping edges of the corner forming member firmly against the wall forming surfaces of the panel sections.
Another object is to provide an inside corner structure for concrete form panel support which provides the requisite strength for holding the parts incident pouring and hardening of the concrete and also has sufficient force generating capability to enable stripping of the adjacent corner form panels and corner angle member from the hardened concrete inside wall corner.
Another object is to provide a control unit for an inside corner structure as described above in which the form panel sections and the corner forming member are elongated and extend at right angles to one another to define the inside corner.
Another object of the invention is to provide a corner forming structure in which the adjacent form panels that are engaged with the angle member at the corner to be cast are positively controlled by a control unit utilizing four bar linkage members to move the panels perpendicularly away from the hardened concrete wall structure.